The long term objective of this Physician Scientist application is to develop an independent academic career in the Molecular Biology of Parasitism. The plan includes an intensive supervised research experience in Molecular Biology of Schistosomes during Phase I which consists of: A. Educational component to provide the applicant with the theoretical and practical tools of modern molecular biology. These will include didactice (graduate school courses), tutorials and a review committee to monitor applicant's overall progress. B. Focused research project to construct cDNA libraries for various stages of Schistosoma mansoni life cycle and to screen these libraries for antigens that may be protective, stage specific or metabolically crucial for parasite survival. The basic science learning and experimental experience of Phase I will insure that the applicant starts Phase II on his way to a career as an independent biomedical investigator. The research activities of Phase II will aim at determining the molecular mechanisms responsible for gene expression in schistosomes, particularly those that regulate biological functions of the parasite. In addition, application of the molecular biology knowledge in an attempt to induce resistance in experimental animals and to study the reactivity of infected populations in endemic areas to crucial parasite antigens will be included. This comprehensive developmental program will be supervised by Dr. Fritz Rottman, Chairman of the Department of Molecular Biology and Microbiology (primary sponsor), and by Dr. Adel Mahmoud, Director of the Division of Geographic Medicine (secondary sponsor).